As passengers grumble about the long lines and delayed flights at crowded airports, at least they can be relieved that travelling is considerably safer than it used to be.

Today is the fiftieth anniversary of a massacre that changed airline security forever.

On 30 May, 1972, in an act that would be almost unimaginable today, three Japanese terrorists simply packed several submachine guns and half a dozen grenades into their suitcases and flew from Beirut to Frankfurt and then on to Rome. There they bought tickets for an Air France flight to Tel Aviv.

Upon arrival at Lod (since renamed Ben Gurion) airport in Tel Aviv, they collected their luggage and within two minutes had indiscriminately shot dead 26 people and wounded 80 others waiting to collect their cases in the arrivals hall. At the time it was one of the worst massacres of civilians at any airport.

The Japanese Red Army terrorists had been recruited by the PFLP faction of the PLO. They were initially trained in North Korea and then flown thousands of miles to Lebanon where they were trained further at a Palestinian base in south Lebanon.

Among those murdered in the Lod airport massacre were 17 Christian pilgrims from Puerto Rico who were planning to tour the holy land; a two-year-old Israeli baby girl; and one of the most eminent scientists in the world, Professor Aharon Katzir-Katchalsky of the Weizmann Institute of Science and former president of the Israel Academy of Sciences. (The Katchalsky crater on the Moon is named after him. His younger brother, Ephraim Katzir, a biophysicist, would later be elected president of Israel.)

The New York Times reported at the time: “At least five grenades exploded amid long bursts of rifle fire. The force of the explosions ripped bodies and luggage alike, leaving blood everywhere. Bullets shattered glass windows and screens throughout the arrival lounge. Holes were splattered in the walls.”

Following the lax security demonstrated at Frankfurt and Rome airports which allowed the terrorists to fly with many guns and grenades in their checked luggage, security was tightened at airports across much of the world, at the request of Israel’s then defence minister, Moshe Dayan.

Israel’s then transport minister Shimon Peres declared: “Tonight, there happened one of the most serious things in the history of aviation. The Government of Israel will take every step to fight this new madness,” he pledged.

The Lod massacre was planned by Wadie Haddad, a Palestinian doctor and graduate of the American University of Beirut, who also organised several civilian airplane hijackings, the most infamous of which was the Entebbe plane hijacking in 1976.

In 1978, he died in communist East Germany, supposedly of leukemia, but other accounts allege that he was poisoned by Israel’s Mossad security agency.

In Striking Back: The 1972 Munich Olympics Massacre and Israel's Deadly Response Aaron Klein, who had been Time magazine’s military and intelligence affairs correspondent, wrote that the chocolate-loving Haddad had been sent Belgian chocolates coated with a slow-acting and undetectable poison which caused him to die several months later. A more recent 2018 book by New York Times journalist Ronen Bergman claims Mossad killed Haddad by poisoning his toothpaste.

According to Vasili Mitrokhin, a senior KGB archivist who defected to Britain in 1992, Haddad’s terror operations were financed by the KGB. Soviet dissident Vladimir Bukovsky revealed a letter by KGB head (and later Soviet president) Yuri Andropov to Leonid Brezhnev about the transfer of arms to the PFLP in which Andropov calls Haddad a “trusted KGB agent”.

Like Haddad, the Japanese terrorists were middle class.

Two were killed during the terror attack but one, 24-year-old Kozo Okamoto, the youngest child of a Japanese school headmaster, was captured. Two years earlier his brother had taken part in the Japanese Red Army hijacking of a plane to North Korea.

In a letter to then Israeli Prime Minister Golda Meir, Okamoto’s father demanded that his son be executed. Israel declined.

Okamoto served only 13 years in jail in Israel before being released in a prisoner swap with the PLO. He was granted asylum in Lebanon where he is regarded as a hero, gave press conferences to western journalists in Beirut in 1985, and has since converted to Islam. (In Tom Clancy’s novel The Sum of All Fears, it is wrongly suggested that Okamoto converted to Judaism.) Now aged 74, Okamoto is said to live a quiet life in retirement in Lebanon.

After the Lod massacre, the Japanese authorities stepped up their crackdown on the Japanese Red Army (JRA) who continued to hijack planes elsewhere up until 1977 and perpetrated other kinds of attacks after then. Eventually, in 2000, they captured JRA leader Fusako Shigenobu. She was sentenced to 20 years in prison and was released on Saturday, 28 May. In March this year, she wrote a letter publically apologising for her acts of terror.

Tom Gross is a former Jerusalem correspondent for the Sunday Telegraph.